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CHAPTER 8 JTAG BOUNDARY SCAN
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(12) Shift-IR
While the TAP controller is in this state, JDI and JDO are connected via the shift register within the
instruction register. The shift data is shifted, one level at a time, to the serial output at each rising edge of
the signal being input to the JCK pin.
The boundary scan register and bypass register selected with the current instruction maintain their
previous states.
While the TAP controller is in this state, instruction conversion is not performed.
While the TAP controller is in this state, at a rising edge of the signal being input to the JCK pin, if the
level of the signal being input to the JMS pin is held high, the TAP controller enters the Exit1-IR state. If
the level of the signal being input to the JMS pin is held low, the TAP controller remains in the Shift-IR
state.
(13) Exit1-IR
Exit1-IR is a state that the controller enters temporarily. In this state, at the rising edge of the signal being
input to the JCK pin, if the level of the signal being input to the JMS pin is held high, the TAP controller
enters the Update-IR state. In this way, scan processing is terminated.
On the contrary, at the rising edge of the signal being input to the JCK pin, if the level of the signal being
input to the JMS pin is held low, the TAP controller enters the Pause-IR state.
Both the bypass register and boundary scan register, selected with the current instruction, maintain their
previous states.
While the TAP controller is in this state, instruction conversion is not performed.
(14) Pause-IR
While the TAP controller is in the Pause-IR state, shift processing by the instruction register is temporarily
halted. The bypass register and boundary scan register, selected with the current instruction, maintain
their previous states.
While the TAP controller is in this state, instruction conversion is not performed. Also, the instruction
register maintains its current state.
While the level of the signal being input to the JMS pin is held low, the TAP controller remains in this
state. At the rising edge of the signal being input to the JCK pin, if the level of the signal being input to
the JMS pin is held high, the TAP controller enters the Exit2-IR state.